Parents should consider state reports that are supposed to reflect the number of violent incidents at Colorado schools with a great deal of skepticism, if not discount them altogether.

The latest evidence to support this conclusion comes in a report by 7News that “the fatal shooting at Arapahoe High School last December was apparently not included in the state’s annual school violence report.”

How can that be? Because the shooter killed himself as well, and schools are obliged to report cases only when a student is disciplined.

Admittedly, that’s a loophole that doesn’t apply to many incidents and so shouldn’t affect overall statistics much. It ought to be fixed, but it’s not necessarily a sign of deeply flawed record-keeping. But the problem is that the Arapahoe High case is a reminder that failure to report violent incidents is actually par for the course for many schools.

A joint investigation by The Denver Post and 7News earlier this year revealed that some schools regularly fail to include assaults and other serious incidents on school discipline data. “Some schools fail to report assaults that police would consider felonies, while others document even the smallest scuffle between elementary students,” The Post’s Zahira Torres reported.

As for Arapahoe High’s failure to report the fatal shooting, it certainly helped keep Littleton schools looking unblemished. “Traditional high schools at Littleton Public Schools have not reported an assault, robbery or felony in the past five years,” Torres found.

Nor was the Post/7News probe the first media report to reveal underreporting of school violence. The problem has been ongoing basically since the reporting mandate was enacted in the wake of the Columbine shootings in 1999.

Ironically, since those two killers shot themselves, they too were never disciplined and so their crimes might never have gone into an official school violence report.